Tweaked MappingMongoConverter to prefer custom Converters.

Before recursively converting values itself, MappingMongoConverter now checks whether the underlying ConversionService can convert the value to be converted into a Mongo basic type itself.

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/convert/MappingMongoConverter.java

@@ -41,6 +41,7 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.expression.BeanFactoryResolver;
+import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.support.ConversionServiceFactory;
 import org.springframework.core.convert.support.GenericConversionService;
@@ -63,6 +64,7 @@ import org.springframework.expression.spel.support.StandardEvaluationContext;
 public class MappingMongoConverter implements MongoConverter, ApplicationContextAware {
 
   private static final String CUSTOM_TYPE_KEY = "_class";
+  private static final List<Class<?>> MONGO_TYPES = Arrays.asList(Number.class, Date.class, String.class, DBObject.class);
   protected static final Log log = LogFactory.getLog(MappingMongoConverter.class);
 
   protected GenericConversionService conversionService = ConversionServiceFactory.createDefaultConversionService();
@@ -377,7 +379,14 @@ public class MappingMongoConverter implements MongoConverter, ApplicationContext
     this.applicationContext = applicationContext;
   }
 
+  /**
+   * Registers converters for {@link ObjectId} handling, removes plain {@link #toString()} converter and promotes the
+   * configured {@link ConversionService} to {@link MappingBeanHelper}.
+   */
   protected void initializeConverters() {
+    
+    this.conversionService.removeConvertible(Object.class, String.class);
+    
     if (!conversionService.canConvert(ObjectId.class, String.class)) {
       conversionService.addConverter(ObjectIdToStringConverter.INSTANCE);
       conversionService.addConverter(StringToObjectIdConverter.INSTANCE);
@@ -386,13 +395,17 @@ public class MappingMongoConverter implements MongoConverter, ApplicationContext
       conversionService.addConverter(ObjectIdToBigIntegerConverter.INSTANCE);
       conversionService.addConverter(BigIntegerToIdConverter.INSTANCE);
     }
+    
+    MappingBeanHelper.setConversionService(conversionService);
   }
 
   @SuppressWarnings({"unchecked"})
   protected void writePropertyInternal(PersistentProperty prop, Object obj, DBObject dbo) {
     org.springframework.data.document.mongodb.mapping.DBRef dbref = prop.getField()
         .getAnnotation(org.springframework.data.document.mongodb.mapping.DBRef.class);
+    
     String name = prop.getName();
+    
     if (prop.isCollection()) {
       Class<?> type = prop.getType();
       BasicDBList dbList = new BasicDBList();
@@ -408,20 +421,52 @@ public class MappingMongoConverter implements MongoConverter, ApplicationContext
         }
       }
       dbo.put(name, dbList);
-    } else if (null != obj && obj instanceof Map) {
+      return;
+    }
+
+    if (null != obj && obj instanceof Map) {
       BasicDBObject mapDbObj = new BasicDBObject();
       writeMapInternal((Map<Object, Object>) obj, mapDbObj);
       dbo.put(name, mapDbObj);
-    } else {
-      if (null != dbref) {
-        DBRef dbRef = createDBRef(obj, dbref);
-        dbo.put(name, dbRef);
-      } else {
-        BasicDBObject propDbObj = new BasicDBObject();
-        write(obj, propDbObj, mappingContext.getPersistentEntity(prop.getTypeInformation()));
-        dbo.put(name, propDbObj);
+      return;
+    }
+
+    if (null != dbref) {
+      DBObject dbRefObj = createDBRef(obj, dbref);
+      if (null != dbRefObj) {
+        dbo.put(name, dbRefObj);
+        return;
       }
     }
+
+    Class<?> basicTargetType = getCustomTargetType(obj);
+
+    if (basicTargetType != null) {
+      dbo.put(name, conversionService.convert(obj, basicTargetType));
+      return;
+    }
+
+    BasicDBObject propDbObj = new BasicDBObject();
+    write(obj, propDbObj, mappingContext.getPersistentEntity(prop.getTypeInformation()));
+    dbo.put(name, propDbObj);
+   
+  }
+
+  /**
+   * Returns whether the {@link ConversionService} has a custom {@link Converter} registered that can convert the given
+   * object into one of the types supported by MongoDB.
+   * 
+   * @param obj
+   * @return
+   */
+  private Class<?> getCustomTargetType(Object obj) {
+    
+    for (Class<?> mongoType : MONGO_TYPES) {
+      if (conversionService.canConvert(obj.getClass(), mongoType)) {
+        return mongoType;
+      }
+    }
+    return null;
   }
 
   protected void writeMapInternal(Map<Object, Object> obj, DBObject dbo) {
@@ -510,7 +555,7 @@ public class MappingMongoConverter implements MongoConverter, ApplicationContext
               continue;
             }
             if (null != entry.getValue() && entry.getValue() instanceof DBObject) {
-              m.put(entry.getKey(), read((null != toType ? toType : prop.getTypeInformation().getMapValueType()), (DBObject) entry.getValue()));
+              m.put(entry.getKey(), read((null != toType ? toType : prop.getMapValueType()), (DBObject) entry.getValue()));
             } else {
               m.put(entry.getKey(), entry.getValue());
             }
@@ -518,7 +563,7 @@ public class MappingMongoConverter implements MongoConverter, ApplicationContext
           return m;
         } else if (prop.isArray() && dbObj instanceof BasicDBObject && ((DBObject) dbObj).keySet().size() == 0) {
           // It's empty
-          return Array.newInstance(prop.getType().getComponentType(), 0);
+          return Array.newInstance(prop.getComponentType(), 0);
         } else if (prop.isCollection() && dbObj instanceof BasicDBList) {
           BasicDBList dbObjList = (BasicDBList) dbObj;
           Object[] items = (Object[]) Array.newInstance(prop.getComponentType(), dbObjList.size());

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/mapping/MappingMongoConverterUnitTests.java

@@ -0,0 +1,106 @@
+package org.springframework.data.document.mongodb.mapping;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import org.joda.time.LocalDate;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.document.mongodb.convert.MappingMongoConverter;
+import org.springframework.data.mapping.BasicMappingContext;
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBObject;
+
+/**
+ * Unit tests for {@link MappingMongoConverter}.
+ *
+ * @author Oliver Gierke
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class MappingMongoConverterUnitTests {
+
+  MappingMongoConverter converter;
+  BasicMappingContext mappingContext;
+  
+  @Mock
+  ApplicationContext applicationContext;
+  
+  @Before
+  public void setUp() {
+    mappingContext = new BasicMappingContext();
+    mappingContext.setApplicationContext(applicationContext);
+    converter = new MappingMongoConverter(mappingContext);
+  }
+  
+  @Test
+  public void convertsAddressCorrectly() {
+    
+    Address address = new Address();
+    address.city = "New York";
+    address.street = "Broadway";
+    
+    DBObject dbObject = new BasicDBObject();
+    
+    converter.write(address, dbObject);
+    
+    assertThat(dbObject.get("city").toString(), is("New York"));
+    assertThat(dbObject.get("street").toString(), is("Broadway"));
+  }
+  
+  @Test
+  public void convertsJodaTimeTypesCorrectly() {
+    
+    List<Converter<?, ?>> converters = new ArrayList<Converter<?,?>>();
+    converters.add(new LocalDateToDateConverter());
+    converters.add(new DateToLocalDateConverter());
+    
+    List<Class<?>> customSimpleTypes = new ArrayList<Class<?>>();
+    customSimpleTypes.add(LocalDate.class);
+    mappingContext.setCustomSimpleTypes(customSimpleTypes);
+    
+    converter = new MappingMongoConverter(mappingContext, converters);
+    
+    Person person = new Person();
+    person.birthDate = new LocalDate();
+    
+    DBObject dbObject = new BasicDBObject();
+    converter.write(person, dbObject);
+    
+    assertTrue(dbObject.get("birthDate") instanceof Date);
+    
+    Person result = converter.read(Person.class, dbObject);
+    assertThat(result.birthDate, is(notNullValue()));
+  }
+  
+  
+  public static class Address {
+    String street;
+    String city;
+  }
+  
+  public static class Person {
+    LocalDate birthDate;
+  }
+  
+  private class LocalDateToDateConverter implements Converter<LocalDate, Date> {
+
+    public Date convert(LocalDate source) {
+      return source.toDateMidnight().toDate();
+    }
+  }
+  
+  private class DateToLocalDateConverter implements Converter<Date, LocalDate> {
+
+    public LocalDate convert(Date source) {
+      return new LocalDate(source.getTime());
+    }
+  }
+}